Speedometer.



J. H. 6: E. W. BULLARD. SPEEDOMETER.

APPLICATION FILED DEG. 21,1906. 935,5 3 Patented Sept. 28,1909.

Ja H. & E. W. BULLARD.

SPE BDOMETBR. APPLICATION FILED DEG. 21,1906.

pt.28,'1909. BETH-SHEET 2 Patented Se STATES PATENT OFFICE.

JAMES H. BULLARD AND EDWIN W. BULLARD, OF SPRINGFIELD, MASSACHUSETTS,

ASSIGNORS T BULLARD SPECIALTY CO.

PORATION OF MASSACHUSETTS.

0F SPRINGFIELD, MASSACHUSETTS, A COR- SPEEDOMETER.

Specification of Letters Patent. Patented Sept. 28, 1909.

' Application filed December 21, 1906. Serial No. 348,904.

' State of Massachusetts, have invented new and useful Improvements inSpeedometers, of which the following is a specification.

This invention relates to speed indicating devices for vehicles andespecially to that class of these devices which are actuated on theprinciple of centrifugal governors, the object of the invention being toprovide a mechanism of this type in which the rota movements of theactuating elements of the mechanism are provided with compensating meanswhereby the movements'transmitted thereby to the indicating pointer maybe, uniform at all speeds, means being provided to render the movementsof the pointer steady during its swinging movement in either direction,regardless of the vibration of its support.

Incidental to the above characteristics is the fact that theconstruction makes it possible to provide an indicating scale havinguniform divisions owing to the uniformity of movement of the indicatingpointer at all speeds. I

Having theseends 1n view, the lnvention consists in mechanlsmshereinafter described and set forth clearly in the claims" andillustrated in the accompanying drawings, in which,;

Fi re 1 is a face View of the instrument showlng the indicating scaleand pointer, and in dotted lines the elbow lever for actuating thepointer. Fig. 2 is a sectional elevation taken on line 2 2, Fig. 1. Thisview shows clearly the connection between the axis of the instrument andone arm of the elbow-lever which actuates the pointer. Fig. 3 is a planview of the instrument looking in the direction of the arrow on line 3of Fig. 2, and showing the internal arrangement of the centrifugallyactuating element and associated parts, the casing portion of theinstrument'bein'g shown in full lines. Fig. 4 is a View of" the rotatingdisk carryingthe centrifugally actuated arms and in 'a posltion atsubstantially the extremity of "the center shaft. and axially movablepin,

' and-the connection between this pin and one end of the elbow-leverwhich imparts movement to the indicating pointer, the parts being shownin separated relation for the purpose of clearness.

Referring now to these drawings, and

specifically to Figs. 1 and 2, mindlcates a Y circular metal casing, theback side I) of which is closed and provided with a hub-like extensionwhich constitutes a bearing for .a tubular shaft 0 to the outer end ofwhich a flexible or other suitable driving-shaft is attached. The shaft6 extends within the casing and has fixed thereto a circular plate '12on which are secured studs e at right angles thereto and equi-distantfrom the center. On these studs are revoliibly mounted the arms fprovided at their extremities with the weights 9, and extending fromthat end of each arm through which the stud e passes, and substantiallyat right angles to said arm is a short projection it having a curvedside or surface is against which the free end of a spring m bears; Thesprings m are supported on the plate din split bosses 0, or in someother suitable way. When the arms f are at rest, the springs will holdthem in the position shown in Flg. 3, that is with their weights g incontact with the periphery of the cam p which is provided on its hubwith a pinion -51 fixed to it so that the cam and pinion are revolvedtogether on the end of the tubular shaft 0 which extends within thecasing, as shown in Fig. 2 very clearly, the cam and pinion being shownalso in perspective in Fig. 5.- On each of the arms f is a segmentalrack 7-. These racks extendone toward the other and engage oppositesides of the pinion g.

The operative surface of the cam p is shown clearly in Figs. 2 and 5,said surface being out in the form of a helix surrounding the inner endof the tubular'shaft c which latter is split lengthwise thereof fora'certain distance, as shown' at s Fig. 5; located axially of this shaftis an endwise movable pin 4) which has fixed in the side thereof a shortI v pin w, which, when the instrument-is at rest, rests on the lowestpart of the helical surface -0 of the cam p, as shown in Fig. 5 and alsoin Fig. 3. y

From the foregoing description, it is seen that the rotation of thetubular shaft 0 will rotate the plate 03 carrying the arms f and thatthe cam p and its attached pinion g, and endwise movable pin '0 alsorotate in unison with the shaft. The rotation of these elements,obviously, will, by centrifugal force, cause the weighted ends of thelevers f to swing apart, and this action, by the engagement of theracks-1 with the pinion Q, will effect the rotation of the cam p and.thus force the pin '0 endwise out of the tubular shaft 0, and anydecrease in the speed of rotation will efi'ect the return movement ofthe weighted ends 9 of the arms f toward the center shaft by. reason ofthe action of the springs m bearing upon the projections h of thesearms. It will be observed that the surface of these projections on whichthe springs bear is curved, as indicated by is,

' the degree of curvature being such that as the arms f swing away fromthe center, the point of contact between these projections and thesprings will move toward the fixed end of the spring, and these partsare so proportioned that the corresponding increase in tension of thesprings, (due to the shortening ofthe springs and the increase in theleverage between the spring and the axis 2: of the arm,) will offset theincreased. momentum of the weighted ends of these arms due to anincreasing speed of rotation, and so counterbalance this increasingmomentum by the automatic shifting of the point of contact of thesprings and the arms h, so that whether the rotation of the plate (Z beat high speed or at alow speed, the degree of separation of the arms fand the consequent amount of rotation .of the cam p will be directlyproportional to the speed, thus permitting the divisions w of theindicating scale shown in Fig. l, to be made uniform. This is quite animportant feature as without the compensating devices for the arms f ordevices having a similar function, the division lines :0, which show themiles per hour would have to be varied; whereas, by means of the presentconstruction, the movement of the indicating pointer 3 will be the samefor the last mile tutes a holding. frame for a glass front 7 of theinstrument. On the same plate 5 at 8, (Figs. 1 and 2 is pivotallysupported an elbow-lever 9 w 'ch 1s clearly shown in dot- I ted lines insaid Fig. 1. One arm of this lever extends to the stud 4' on which thepointer is fixed, and the other arm of the lever extends toward thevertically movable pin 4; at the axis of the instrument,

its end lying in proximityto said pin. On

the plate 5 is pivotally supported by means of a bracket arm 10 thesmall elbow-lever 10 whose axis is .at right angles to the pin 4) andone end of this lever bears on the end of the pin 11, and the other endagainst the end of the arm of the elbow-lever 9 which extends toward thecenter of the instrument. A spring 12 (shown clearly'in Fig. 2) bears onthe other arm of the lever 9, whereby the arm of the latter which liesover the pin o and the short elbow-lever 10 are constantly held incontacting .relation, and said elbowlever 10 also is constantly held incontact with the end of the pine. By means of this construction no lostmotion can occur between the vertical movement of .the pin "a and thehorizontal movement of the elbowlever 9. On the revoluble stud 4 is apin 14:; parallel with the axis of said stud, and against which thespring 12 bears, as shown in said Fig. 1,'and whereby the pin is held incontact with that end of the elbow-lever 9 which terminates near saidstud.

' From the foregoing description, it is clear that into whateverposition the pointer 3 may be moved by the centrifugal separation of theweighted arms f, it can not be vibrated and made to swing indefinitelyin the vicinity of one or more of the indicating lines 00 of the scale,whether it be moving in one direction or the opposite. This is a veryserious defect with some of the indicating devices as at presentconstructed, but with 'th1s mstrument it is entlrely overcome owing tothe fact that all of the parts which would effect this tremblingmovement of the pointer are held constantly in contact with each other,and at whatever speed the arms f may be rotating at that particularinstant.

From the foregoing description the vertical movements of the pin '1) areconverted into a horizontal movement by means of the lever 10 operatingon the end of the arm of the lever'9 which lies over the pin '21 at thecenter of the instrument, whereby the pointer 3 is moved by means of theother arm of the lever 9. and pin 14 over the divisions of the scale.What we claim is 1. A speedometer comprising a rotatable shaft,centrifugally actuated arms, the free ends of which swing away from theshaft during the rotation of the-latter, said arms.

each having a projection extending at an angle therefrom and providedwith a curved edge; springs fixed at one end and carried by the shaft,and bearing against the curved edges of said projections, the efiectivelength of the springs being changed by the swinging movement of theprojections on which they have a bearing, and an indicating pointeractuated by the swinging movement of thevarms, an elbow lever having onearm operatively engaging the pointer, its other am being actuated by asecondelbow lever,

the latter being pivoted so as to move in a I so the axis of the shaplane at right angles to the plane of the first mentioned elbow lever,as described.

2. A speedometer comprising a hollow, rotatable shaft, a member carriedthereby, centrifugally'actuated arms supported on said member andcarried by the shaft, a pinion loose .on the shaft, and racks on thearms engaging the pinion, an endwise movable pin located axially insaid.- shaft, and a cam on the pinion, said pin bearing on the cam,whereby the rotation of the pinion b thecentrifugal movement of. thearms wil impart endwise movement to the pin, an indicating. pointersupported to swing at right angles to the axis of the shaft, anelbowlever having one end engaging the pointer and its 0 posite end nearthe shaft, and a second el w-lever bearin on the pin and the adjacentarm of the e bow-lever, and a spring bearing on thelatter to hold it ande second elbow-leverconstantly in contact with thepin.

3. A speedometer of the class described having in combination arotatable shaft, a centerin movabl mounted therein, centrifug y actuatemeans for efi'ecting the movement of the center-pin, a pointer pivotallymounted in a fplane at right angles to on the pointer, a lever havingan. arm engaging one sideof the abutment; a spring engaging the oppositeside of the same, whereby the pointer is normally gripped and rotatedtoward zero position, and means engaging a second arm of the elbow-leverand the center-pin whereby the axial movement of the center pin istransformed into amovement in'a plllalme at right angles to the shaft.

4. combination with the pointer of a speedometer, an operating lever forthe same, a elariiied by the pointer and in plontact w1t t e ever, a sp-en f t e in the latter being locafi betv v eefi i e spl ing and'levei',whereby vibration of the pointer is prevented, and centrifugallyactuated means to. swing the lever, the centrifugally a weighted armhaving a projection integral therewith, the projection having a curvededge, and a spring engaging the curved edge. v

an abutment mounted 5. A speedometer having in combination, a pivotallymounted pointer, an abutment carried by the hub portion thereof, anoperating lever one arm of which engages and extends past one side ofthe abutment, an elastic element engaging and extending past theopposite side of the abutment, an centrifugally actuated means fordirectly actuating the lever, whereby the ointer is operated asdescribed, said centrifugally actuated means being provided with aprojection having a curved edge, and a spring engaging said edge.

6. A speedometer having in combination, a pointer, an abutment thereon,an elbowlever, one arm of which engages one side of the abutment, a leafspring enga ing the opposite side of the abutment, and serving tomaintain .thepointer in zero position, whereby the pointer is grippedand main tained against vibration, a rotatable shaft, an endwise movableelement mounted therein, centrifugally actuated means for moving'theelement in an outward direc-- ated means including an arm having aweighted end and a projection integral with the arm, the projectionhaving a curved edge and a spring engaging the curved edge. 7 A seedometer having in combination, a rotatable shaft, a pin mountedtherein, centrifugally actuated means for moving the pin in an outwarddirection, a pointer adapted for movement in a lane transverse to theaxis of the shaft, an a utment carried by the pointer, an elbow leverhaving one arm engaging the abutment, an elastic element engaging theother side of the abutment, a second elbow lever. located between theother end of the first mentioned elbow-lever and the pin, whereby, thepointer is actuated by the centrifugally actuating means when the pin ismoved in an outward direction, as described.

JAMES H. BULLARD.

EDWIN W. BULLARD.

Witnesses:

Win-H. Cnmrm, K.'I. Ominous.

